直升机飞行中的涡环状态研究

针对直升机特有的涡环飞行状态,根据直升机空气动力学理论,分析了直升机涡环状态飞行事故的现象及成因。指出研究直升机涡环状态的关键是确定涡环状态的边界,分析了各种涡环边界试验的结果及特点,并比较了计算确定涡环边界所需的各种边界判据的特点。最后提出了预防直升机涡环事故的被动方法和主动方法,指出研制涡环告警装置是减少直升机涡环状态飞行事故、保证飞行安全的有效途径。并就建立直升机涡环状态预防体系提出了建议。

Research of vortex-ring state of helicopter flight

To investigate helicopter vortex-ring state, the phenomenon and reason of helicopter vortex-ring state flight accident is analyzed from the view of helicopter aerodynamics. It is stated that the key is to determine the vortex-ring boundary, the result and the characteristic of vortex-ring state test research are summarized, and the rationality of some kinds of vortex-ring state criterion which determine the vortex-ring boundary is analyzed. At last, the active and passive methods to prevent helicopter from vortex-ring accident are put forward, and it is pointed that the vortex-ring alarm device is the effective routine to reduce helicopter vortex-ring state flight accident and assure flight safety, and it is suggested to form the system of helicopter vortex-ring prevention.